A. Idris, A. C. Linatoc, A. M. Aliyu, S. M. Muhammad, and M. F. B. A. Bakar, “Effect of Light on the Photosynthesis, Pigment Content and Stomatal Density of Sun and Shade Leaves of Vernonia Amygdalina”, IJET, vol. 7, no. 4.30, pp. 209–212, Nov. 2018, doi: 10.14419/ijet.v7i4.30.22122.